Brake mechanism

ABSTRACT

A brake mechanism includes a connecting element that is fixed to a wheel axle of a motor vehicle or is embodied monolithically therewith, and a fastening flange of a disk brake caliper. The fastening flange is fixed to the connecting element. The brake mechanism is configured in such a way that the fastening flange is retained in a positive manner on the connecting element in the circumferential direction of the wheel axle.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to a brake mechanism.

Preferably disk brakes which are actuated by compressed air, inparticular for commercial vehicles, are fastened in each case to aconnecting element which is connected fixedly to the wheel axle by afastening flange of the brake caliper or a brake carrier of the diskbrake being screwed to the connecting element.

This type of fastening is shown and described, for example, in EP 0 849486 A2. Here, the connecting element and the fastening flange of thebrake caliper bear with their full surface area against one another,that is to say in an overlapping manner, and are screwed to one anotherby screws which extend in the axial direction of the wheel axle.

Although satisfactory positioning of the brake caliper is achieved as aresult, the exclusively force-transmitting connection is associated withsome disadvantages which stand in the way of long-term optimum operationof the disk brake.

During the braking operation, a torque becomes active as a result of theapplied braking force or as a result of the friction forces which act onthe brake disk, which torque has to be absorbed by the screw connectionswhich in each case comprise a through hole, a threaded hole and a screw,it being possible for the through hole to be provided in the connectingelement or fastening flange and for the threaded hole to be provided inthe other associated component.

In order for the screw to pass through, the diameter of the throughwhole has to be greater than the shaft diameter of the screw. Inparticular in the case of high braking moments which are not transmittedby the force-transmitting connection, this leads to a relative movementof the component which has the through hole with respect to the othercomponents, until the interior of the through hole comes into contactwith the screw shaft. As a result, the screws are subjected to shearforces to a considerable extent, which makes correspondingcross-sectional dimensioning necessary which counteracts inexpensivemounting and a weight-optimized construction.

It is also problematic that this type of connection requires arelatively large number of connection screws, which necessitates largebearing faces of the connecting element and the fastening flange.

As a result of the abovementioned relative displacement of thecomponents which are connected to one another during braking, thesliding guide of the brake caliper in a sliding caliper brake can bestressed, which leads to long-term damage of the guide parts. Moreover,in the case of reversing operation, the frequent to and fro displacementof the components can lead to loosening of the screws, as a result ofwhich the operational security can be impaired overall.

One further disadvantage of the known fastening type is the pooraccessibility of the screws; as screwing has to take place from thevehicle inner side, mounting and dismantling of the brake is madedifficult.

It is known from DE 200 21 587 U1 not to arrange the screws coaxiallywith respect to the rotational axis of the disk brake, but tangentiallywith respect thereto. Although this construction makes improvedaccessibility of the screws possible during mounting and a reduction inthe brake weight as a result of the possible smaller bearing faces ofthe connecting element and the fastening flange, the relativedisplaceability of the two components with respect to one another duringthe transmission of the braking moments to the axle still exists, withthe above-described disadvantages.

The present invention is therefore based on the object of developing abrake mechanism of the generic type in such a way that it can bemanufactured and mounted or dismantled inexpensively, weight reductionof the brake overall is achieved and the operational security isimproved.

This object is achieved by a brake mechanism having a connecting elementwhich is fastened to a wheel axle of a motor vehicle or is configured inone piece with the latter, and a fastening flange of a brake caliper ora brake carrier of a disk brake, the fastening flange being fastened tothe connecting element, wherein the fastening flange is held in aform-fitting manner on the connecting element in the circumferentialdirection of the wheel axle.

As a result of this structural configuration, the braking moment is nowabsorbed by a form-fitting connection and not, as in the prior art, by aforce-transmitting connection. Relative displacement of the fasteningflange with respect to the connecting element is therefore precluded.

This results first of all in an improvement in the operational security,as, for example in the case of a sliding caliper brake, the guide partscan no longer be stressed with respect to one another and, duringreversing operation, loosening of connection screws is precluded.

As they no longer serve to accommodate the screws, but exclusively forthe form-fitting connection, the contact faces of the two components canbe kept relatively small, which contributes to a weight saving and tothe optimization of manufacturing. The same is true analogously for thereduced number of connections screws which is then possible, as these inpractice serve only to hold the two components against one another.

The associated reduction in the space requirement makes substantiallyimproved accessibility to the screws possible, with the result thatmounting and dismantling of the brake is possible in a substantiallysimpler manner.

According to one advantageous development of the invention, there isprovision for the contact faces of the fastening flange on one side andof the connecting element on the other side to extend in a manner whichis oriented obliquely toward the center of the wheel axle, with theresult that the respective two contact faces lie in a V shape withrespect to one another. Here, the fastening flange in practice forms awedge which is supported laterally on the connecting elements.

During brake mounting, this V shape makes simple, predefined positioningpossible, which likewise simplifies mounting.

Further advantageous refinements of the invention are described andclaimed herein.

BRIEF DESCRIPTION OF THE DRAWING

In the following text, one exemplary embodiment of the invention will bedescribed using the appended drawing.

The single FIGURE shows a brake mechanism according to the invention ina perspective illustration.

DETAILED DESCRIPTION OF THE DRAWING

The FIGURE shows a brake mechanism which, in its basic construction,comprises a connecting element 1, a fastening flange 3 and a brakecaliper 2 which is formed here in one piece with the latter.

The connecting element 1 is fastened to a wheel axle (not shown), forexample by welding, for which purpose the connecting element 1 has apush-in bore 7, in order to accommodate the wheel axle. In one designvariant, the connecting element 1 can be configured in one piece withthe axle body as a cast part or forging.

Overall, the connecting element 1 is of plate-shaped and, here,mirror-symmetrical configuration. Connecting limbs 4 are formed on bothsides, which lie in a V shape with respect to one another and havecontact faces 6, against which fastening limbs 8 of the fastening flange3 bear. Accordingly, the fastening limbs 8 likewise together form a Vshape, in relation to the faces which face the contact faces 6. The Vhas an opening angle α with respect to the center longitudinal axis L ofthe connecting element. The center longitudinal axis L extends throughthe tip of the V.

In principle, every angle which is less than 90° is conceivable, belowwhich the respective contact face 6 is oriented toward the centerlongitudinal axis of the connecting element 1. The contact faces 6preferably lie in each case at an angle 2 a of from 10 to 80° withrespect to one another, preferably from 30 to 60°, in particularapproximately 55°, with very particular preference 58°, as results whichare improved further can be achieved in each case in a surprising mannerat these angles.

The fastening limbs 8 and therefore the brake caliper 2 are connected tothe connecting element 1 by connection screws 5 which extend preferablytangentially with respect to the wheel axle or with respect to thepush-in bore 7, the heads of the connection screws 5 being supported onsupporting faces of the connecting limbs 4, which supporting facesextend parallel with respect to the respective contact face 6.

As can be seen clearly, the connecting limbs 4 form an abutment forabsorbing braking moments which occur and are active in thecircumferential direction of the push-in bore 7 or the wheel axle (notshown). Shear loading of the connection screws 5 is precluded here.

TABLE OF REFERENCE NUMBERS

-   1 Connecting element-   2 Brake caliper-   3 Fastening flange-   4 Connecting limb-   5 Connection screw-   6 Contact face-   7 Push-in bore-   8 Fastening limb

1. A brake mechanism, comprising: a connecting element operativelyadapted for being fastenable to a wheel axle of a motor vehicle or beingconfigured in one-piece with the wheel axle; a fastening flange of atleast one of a brake caliper and brake carrier of a disk brake, thefastening flange being fastened fixedly to the connecting element;wherein the fastening flange is adaptively configured to be held in aform-fitting manner on the connecting element in a circumferentialdirection of the wheel axle; wherein the fastening flange and theconnecting element have, in each case, contact faces which bear againstone another and extend, in each case, at an acute angle α of less than90° with respect to a center longitudinal axis of the connectingelement; and wherein the contact faces are arranged so as to extend in aV shape with respect to one another.
 2. The brake mechanism as claimedin claim 1, wherein the contact faces are arranged in amirror-symmetrical manner about the center longitudinal axis of theconnecting element with respect to one another.
 3. The brake mechanismas claimed in claim 1, wherein the connecting element has two connectinglimbs, the sides of which face the fastening flange form, in each case,the contact face.
 4. The brake mechanism as claimed in claim 1, whereinthe contact faces enclose an angle 2α of less than 90° with respect tothe center longitudinal axis of the connecting element.
 5. The brakemechanism as claimed in claim 1, wherein the contact faces enclose anangle 2α of between 20° and 70° with respect to the center longitudinalaxis of the connecting element.
 6. The brake mechanism as claimed inclaim 1, wherein the contact faces enclose an angle 2α of between 30°and 60° with respect to the center longitudinal axis of the connectingelement.
 7. The brake mechanism as claimed in claim 1, wherein thecontact faces enclose an angle 2α of approximately 55°.
 8. The brakemechanism as claimed in claim 1, wherein the contact faces enclose anangle 2α of approximately 58°.
 9. The brake mechanism as claimed inclaim 1, wherein the connecting element is formed in one piece as a castpart with the wheel axle or with an axle element.
 10. A brake mechanismcomprising: a connecting element operatively adapted for beingfastenable to a wheel axle of a motor vehicle or being configured inone-piece with the wheel axle; a fastening flange of at least one of abrake caliper and brake carrier of a disk brake, the fastening flangebeing fastened to the connecting element; wherein the fastening flangeis adaptively configured to be held in a form-fitting manner on theconnecting element in a circumferential direction of the wheel axle,wherein the fastening flange and the connecting element have, in eachcase, contact faces which hear against one another and extend, in eachcase, at an acute angle α of less than 90° with respect to a centerlongitudinal axis of the connecting element, wherein the connectingelement has two connecting limbs, the sides of which face the fasteningflange form, in each case, the contact face, and wherein each connectinglimb has supporting faces which extend parallel with respect to theassociated contact face and on which heads of connection screws aresupported, which connection screws are screwed into the fasteningflange.
 11. The brake mechanism as claimed in claim 10, wherein theconnection screws are arranged so as to extend tangentially with respectto the wheel axle.
 12. The brake mechanism as claimed in claim 10,wherein the fastening flange is provided with two fastening limbs, ofwhich each is assigned to a connecting limb of the connecting elementand bears against the contact face.
 13. The brake mechanism as claimedin claim 12, wherein each fastening limb bears over its full contactface against the contact face of the associated connecting limb.